The printed part needed for the UBS Extension upgrade, Prusa Mini (+).
The V1 version isn't 100% compatible with the backplates. V2 will be available soon.
This is the version with the USB port on the side, the version with the USB port on the front can be found here.
They are printed in PETG Prusa Orange and PETG Jet Black to match the colours of the original Prusa mini.